1. Field of the Invention
The present invention relates to a printing control apparatus and, more particularly, to a printing control apparatus, a printing system, a recording medium having recorded thereon a printing control program, and a printing control method performing a rasterizing process.
2. Description of Background Art
A printing system is generally made up of a printing control apparatus and a printer. The printing control apparatus receives manuscript data from an external Personal Computer (PC). The manuscript data is data generated by editing parts to be used in each page and laying them out, and described in Page Description Language (PDL). The printing control apparatus performs a rasterizing process (hereinafter, described as an “RIP process”) by an Raster Image Processor (RIP) on the received manuscript data to generate printing output data. The printing output data includes data obtained by the RIP process (hereinafter, called “RIP-processed data”), and synthesis information used for synthesizing the RIP-processed data in the printer. The printing output data is transmitted to the printer. The printer outputs a printed matter based on the received printing output data. In the printing industry, to achieve reduction in print cost, an increase in speed of processes performed by a printing system (hereinafter, called a “printing process”) as described above is in demand.
Japanese Patent Application Laid-Open Publication No. 2011-67993 discloses an image processing apparatus performing the RIP process by a plurality of RIP processing units in parallel. The image processing apparatus corresponds to the above-described printing control apparatus. Hereinafter, the RIP process performed in parallel will be called a “parallel RIP process”. By such a parallel RIP process, the speed of the RIP process can be increased. To the plurality of RIP processing units, a cache memory is connected. In the cache memory, RIP-processed data obtained by the RIP process in the RIP processing units is cached. Consequently, with respect to a reuse part as a part which is repeatedly used in a plurality of pages, its RIP-processed data is cached for the first time, and the cached RIP-processed data is used for the second time on. In such a manner, the speed of the RIP process can be further increased. RIP-processed data of each part is transmitted to a printer for each page in which the part is used. The parallel RIP process is disclosed also in United States Patent Application Publication No. 2004/95596 and Japanese Patent Application Laid-Open Publication No. 2006-39719. The RIP process using a cache is disclosed also in Japanese Patent Application Laid-Open Publication No. 2009-71352.
In the technique disclosed in Japanese Patent Application Laid-Open Publication No. 2011-67993 and the like, however, even RIP-processed data corresponding to a reuse part is transmitted from a printing control apparatus to a printer for each page used. Consequently, in the case where a reuse part exists, although the speed of the RIP process can be increased, the speed of the entire printing process cannot be sufficiently increased.